'Explosion' of Sex-Spread Hepatitis C in HIV-Positive Men

July 21, 2011 -- There is an ongoing "explosion" of deadly hepatitis C among men who have sex with men.

It's spread mainly by anal sex, often enhanced by methamphetamine, according to a report in the July 21 issue of the CDC's Morbidity and Mortality Weekly Report.

"We are having an explosion of sexually transmitted hepatitis C," study researcher Daniel S. Fierer, MD, of New York's Mount Sinai School of Medicine, tells WebMD. "We have uncovered an emerging epidemic of sexual transmission of hepatitis C. And the main reason is men having anal sex without a condom."

It's no surprise to experts who treat hepatitis C. Liver cancer and cirrhosis caused by hepatitis C virus (HCV) already is the leading cause of death among people with HIV infection who have access to HIV drugs. Some 30% of Americans with HIV are co-infected with HCV.

Sexual transmission of HCV among people without HIV is rare, notes Eugene R. Schiff, MD, director of the Center for Liver Diseases at the University of Miami, who was not involved in the Fierer/CDC study. Among heterosexual couples, he says, only 2% of those with HCV infect their partners after 20 years of monogamous marriage.

The same may be true for men who have sex with men -- if they practice safe sex.

"Our data do not support sexual HCV transmission between HIV-negative men," Fierer says. "There is reasonable data that HIV-negative men are not part of this epidemic."

But that's not the case for HIV-positive men, notes Lynn E. Taylor, MD, of Brown University. Taylor was not involved in the Fierer study. In a study published last March, Taylor and her colleagues showed that new HCV infections are relatively common among HIV-positive men who do not use intravenous drugs -- a phenomenon previously reported in Europe and Australia.

"We have robust evidence of increasing HCV incidence among men who have sex with men who do not inject drugs but do engage in high-risk sexual behaviors," Taylor, who was not involved in the Fierer study, tells WebMD. "It is the new sexually transmitted infection in this population. I am very concerned."